Table o contents

The Siller Y is a middlin-sized moch wi a wingspan o 30 tae 45 mm. The wings are intricately patterned wi various shades o broun an grey providin excellent camouflage. In the centre o each forewing thare is a siller-coloured merk shaped lik a letter Y or a Greek letter Gamma. Thare are several different fuirms wi varyin colours dependin on the climate in which the larvae grow.

The species is widespread athort Europe, pairts o Asie, an North Africae. It is resident in the sooth o its range an adults flee amaist throuoot the year. In Hairst variable nummers migrate north reachin as far as Iceland, Greenland, an Finland wi huge invasions takkin place in some years. A seicont wave o migrants arrives in the Simmer. In central Europe an the Breetish Isles adults are present in significant nummers frae Mey onwairds wi nummers dwindlin in late Ware as thay are killed aff bi frosts. Some indwallers flee sooth again tae winter aroond the Mediterranean an Black Seas.

Siller Y motcs can produce twa or three generations in a year wi a fowert generation when condeetions are pairticularly guid. The eggs are laid on the upper or lawer surface o leaves. Thay are whitish in colour an hemispherical in shape wi deep ribbin. Thay hatch efter three tae fower days (langer in ceul condeetions).

The larvae are aboot 30 mm lang, hae three pairs o prolegs an are uisually green wi whitish markins. Thay feed on a wide variety o law-growin plants an hae been recordit on ower 200 different species includin crops sic as the garden pea (Pisum sativum), succar beet (Beta vulgaris) an cabbitch (Brassica oleracea).[1] Thay can reduce crop yields bi damagin leaves an are aften considered tae be a pest.

The pupa is green at first, gradually darkenin tae black. The adults mate ane or twa days efter emergin frae the pupa an stairt layin eggs ane tae five days later. Thay dee three tae nineteen days efter emergence.